The present inventive concepts relate to an optical modulator and, more particularly, to an optical phase modulator.
In order to display natural 3D images, a holographic 3D image display has recently been studied. Light may be regarded as having wave-like characteristics such as intensity and phase, and holographic technologies are used to display images by controlling the phase and intensity of light. Thus, a holographic 3D image display requires a device to control an amplitude (intensity) or phase of light.
Technologies for modulating amplitude and phase of incident light are being developed to implement a space light modulator (SLM) displaying holographic images. The amplitude modulation technology is to electrically control transmittance or reflectance of light, and the phase modulation technology is to control phase of light transmitted or reflected.
Nowadays, liquid crystals are principally used for the space light modulator using the phase modulation technology. A viewing angle is considered as an important factor determining performance characteristics of the holographic image display. As the viewing angle improves with decreasing pixel pitch of the space light modulator, the holographic image display is increasingly required to have a fine pixel pitch. However, when the space light modulator using the liquid crystals has a small pixel pitch, a fine pitch device may be hardly achieved due to pixel interference inevitably caused by a spreading phenomenon of an applied electric field.